Weigh scale blender

ABSTRACT

A weigh scale blender comprising a frame, a weigh bin, a load cell connected to the frame for sensing weight of the bin and any material contained therein, a mix chamber connected to the frame, including a mixing paddle therewithin, a dump flap for selectably releasing material from the bin into the mix chamber, a bushing intermediate the load cell and the frame for damping transfer of vibration and shock motion therebetween.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is a division of U.S. Ser. No. 08/763,053, filedDec. 10, 1996, now U.S. Pat. No. 6,007,236, which discloses subjectmatter in common with and is entitled to the benefit of the filing datesof U.S. provisional application Ser. No. 60/008,498, filed Dec. 11, 1995in the name of Stephen B. Maguire and entitled “Gravimetric Blender withTool Operated Solenoid Valve Override and Axially Self-AligningMotor-Mixer Coupling” and No. 60/016,064 filed Apr. 23, 1996 in the nameof Stephen B. Maguire and entitled “Gravimetric Blender/Liquid ColorPump Combination”.

BACKGROUND OF THE INVENTION

This invention relates generally to providing precisely measured amountsof granular materials and, optionally, precisely measured amounts ofcoloring agent(s), particularly pigment in liquid form, preparatory tofurther processing of the combined granular materials and, optionally,liquid coloring agent(s), and specifically to weigh scale blenders,optionally in combination with color addition pumps, providing preciselymeasured amounts of plastic resin material, and, optionally liquidcoloring agents, and mixing these components prior to supplying theblended mixture to plastics manufacturing and processing equipment suchas plastic injection molding, compression molding and extrusionequipment.

FIELD OF THE INVENTION AND DESCRIPTION OF THE PRIOR ART

The modern weigh scale blender was essentially originated by theapplicant and is widely used throughout the world by industriesconcerned with precision feeding of granular material, especiallyplastic resin material.

Weigh scale blenders operate by blending solid plastic resin materialcomponents and additives, by weight, in batches. Typically batches ofmaterial may consist of several solid material components. One of thesemay be “regrind”, consisting of ground plastic resin which hadpreviously been molded or extruded and which either resulted in adefective product or was excess material not formed into a desiredproduct.

Another component may be “natural” plastic resin which is virgin innature in the sense that it has not previously been processed into amolded or extruded plastic part.

Yet another component may be a solid color material, typically flakes orfreeze dried material, used to produce a desired color of the finishedplastic part.

Still yet another component may be an additive used to adjust the blendto provide required performance characteristics during molding,extrusion or subsequent processing.

The weigh scale blender typically includes hoppers for each of thecomponents of the solid material to be blended together. Typicallyseveral hoppers or several compartments in a hopper may be provided,such as one compartment for “regrind” material, one compartment for“natural” material, one component for solid color additive material andone compartment for “additive”.

When the weigh scale blender operates, the unit desirably operatesautomatically, adding each of the component solid materials in theproper, desired percentages. Each solid material component is dispensedby weight into a single weigh bin. Once the proper amounts of eachcomponent have been serially dispensed into the weigh bin, all of thecomponents are dropped together into a mixing chamber from the weighbin.

Mixing is performed, preferably continuously, and preferably even asadditional batches component are dispensed in the mixing chamber. Whenmixing is complete, the resulting blend is preferably provided directlyto the desired molding or extrusion machine.

It is known to provide feedback control of the dispensed amounts of eachsolid material component provided to the weigh bin and measured byweight so that in the event of an error in the amount of a dispensedcomponent, the succeeding batch may have the blend adjusted to accountfor the error detected in the preceding batch of blended material.

As one of the components forming a part of the resulting blend it isknown to supply solid color additives to the blend in order to provide ablend of a desired color. These color additives may be flaked pigmentson wax carriers or in freeze dried form. It is also known to provide thecolor as pigment powder constituting one component of the resultingblend.

When preparing blends of resinous plastic material for molding orextrusion, when color amounts are too low the error is visible and acorrection to increase color may be effectuated by an operator. However,when color amounts are too high, the problem is not visible andoperators manually operating the process normally do not make anyadjustment in the amount of color. Hence adjustments are frequently madeto increase the amount of color materials supplied to a blend but almostnever is the amount of color supplied to the blend reduced.

Liquid color material cannot be preblended into one of the solidmaterial components and stored because of the danger inherent anddifficulties attendant to clean-up in the event of component failure.Hence, liquid color, when used in plastics material processingheretofore, has been metered directly into the throat of a molding pressor an extrusion machine, at a position to join the solid resinousmaterial blend just prior to the molding or extrusion operation. Thisapproach creates difficulties, among them being compensating foraddition of pre-colored regrind solid material to the material mix.

When regrind is added to the blend of plastic resin materials, theregrind already contains the necessary color; such regrind need not becolored a second time. When metering resinous material at the throat ofa molding press or an extrusion machine, such metering is conventionallyperformed volumetrically. Hence, the presence of already coloredregrind, not requiring additional coloration, cannot be detected. As aresult, excess liquid color is typically added to the blend, sometimesproducing an unacceptable product and always resulting in the use ofunneeded color material, which is undesirable and results in unnecessaryexpense.

Weigh scale blenders typically use one or more load cells to detect theweight of the weigh bin and material contained therein. Vibrational andshock loading of the load cells may result in erroneous measurements ofthe weight of the weigh bin and the material contained therein. Theseerroneous measurements may result in addition of excess material or aninsufficient amount of a material component in a subsequent batchthereby producing a batch of blended material deviating from the desiredspecifications. The load cells are subject to some vibration and shockloading due to the presence of pneumatic piston-cylinder combinationstypically connected to the frame of the weigh scale blender and used todispense solid granular resinous material from a hopper downwardly intothe load bin.

Further vibrational and shock loading of the load cells may result fromuse of typically pneumatically driven piston-cylinder combinations toempty the weigh bin when the weight measurement is complete. Yet furthervibrational and shock loading of the load cells may result fromoperation of the mixing chamber and the motor driving a mixing meanswithin the mixing chamber.

Because the frame of the weigh scale blender must be a rigid, highstrength structure to provide the required strength to support thematerial storage hoppers and other components of the weigh scaleblender, the weigh scale blender frame is typically steel. Since theframe is steel and rigid, shock and vibrational loads applied to theframe are readily transmitted along the frame and received by thevarious components of the weigh scale blender connected to the weighscale blender frame.

When the weigh scale blender is mounted directly on a plastics materialprocessing machine such as an extruder or, more particularly, aninjection molding machine, the load cells of the weigh scale blender canbe subjected to very substantial shock and vibrational loading.Injection molding machines have heavy steel platens and molds which openand close as parts are molded and ejected. There is a considerableamount of movement in an injection molding machine and the parts whichmove are heavy. Hence shock loads, which continuously propagatethroughout injection molding machines and hence propagate through theweigh scale blender when the blender frame is bolted to the injectionmolding machine, maybe quite substantial.

In weigh scale blenders utilizing single load cells, loads on a cell maybe substantial. In single load cell weigh scale blenders the single loadcell has the weight of the weigh bin cantilevered on an arm and the cellbears the entire weight of the weigh bin and the material containedtherein. Hence vibrational loading of the frame of the weigh scaleblender may produce substantial vibrational loading of the load cellwith stress to the load cell due to the weight carried by the load cell.The cantilevering of the weigh bin from the load cell results in highmoments of inertia being applied to the load cell when the load cell issubject to vibration and shock loading.

SUMMARY OF THE INVENTION

In one of its aspects this invention provides a weigh scaleblender/color addition pump combination where the weigh scale blenderincludes a frame, a hopper supported on the frame, a weigh bin below thehopper and load sensing means mounted on the frame for sensing weight ofthe bin including material contained within the bin.

The weigh scale blender further preferably includes preferably pneumaticpiston-actuated means, preferably connected with the hopper, forreleasing material within the hopper towards the weigh bin. A mixchamber preferably below the bin preferably includes mixing meanstherewithin.

The weigh scale blender preferably further includes pneumaticallyactuated means for releasing material within the bin into the mixchamber. A motor preferably rotates the mixing means.

Respecting the combination of the weigh scale blender and the coloraddition pump means for supplying liquid color to the material mix forblending therewith, the pump means supplying liquid color may desirablybe a peristaltic pump or a progressive cavity pump. The liquid color issupplied by such a liquid pump in an amount measured by weight in theblender, in the same manner as the other, solid material components ofthe resulting material blend are added. Peristaltic pumps are preferred.

Gravimetric blending using a weigh scale blender of the type to whichthis invention relates permits detection of the presence of coloredsolid regrind material and resultant adjustment of the amount of liquidcolor being added. This invention, in one of its aspects combining aliquid color supply pump with a weigh scale blender resulting inaddition of liquid color to the material blend provides many of the sameadvantages as when blending just dry plastic powder and concentratedplastic resin pellets.

When these granular solid and liquid materials are added to the weighscale blender there is precise metering, no over-coloring and no dangerof recoloring regrind material. Hence liquid color material may be addedand metered using the same techniques as solid plastic resin material,which techniques are considerably easier, more efficient and moreaccurate than liquid color handling techniques.

In another of its aspects this invention embraces preparing plasticresin material for manufacturing processing such as molding orextrusion. This includes preferably serially metering respective solidresinous materials to the weigh station until pre-selected weights ofthe respective materials are at the weigh station. This further includesmetering liquid color to the weigh station to join at least one of thematerials which have been metered to the station until a pre-selectedweight of liquid color is at the weigh station. This further includesproviding the serially metered solid materials and the pre-selectedweight of liquid color material unitarily to a mixing station. Thisfurther embraces mixing the unitarily supplied preferably seriallymetered solid granular materials and a pre-selected weight of liquidcolor into a blend preparatory to manufacturing processing via moldingor extrusion.

The monitoring is preferably performed continuously and digitally.

The metering of liquid color is preferably performed peristaltically.

In another of its aspects the invention may provide spring-loadedsolenoid valve means for actuating the means for releasing materialwithin the hopper, preferably by applying pneumatic pressure to a pistonassociated with the hopper material releasing means.

The weigh scale blender may further include means for enclosing thesolenoid valve means thereby preventing finger actuation of the solenoidvalve means. The weigh scale blender may yet further include manuallycontrolled means, adapted for passage through the enclosure means, foroverriding the solenoid valve means to result in application ofpneumatic pressure to the piston of the hopper material releasing meansthereby releasing any material within the hopper and permitting gravityinduced flow thereof.

The spring-loaded solenoid valve means for actuating the means forreleasing material within the hopper by applying pneumatic pressure to apiston of the hopper material releasing means may include a pressurizedair manifold, conduits pneumatically communicating with respective sidesof the piston and valve means including a movable stem defining aportion of the valve exterior, for selectably connecting the conduits tothe manifold, thereby to move the piston in a selected direction andhence the associated material releasing means between open and closedpositions.

There may further be provided a spring for biasing the stem of the valvemeans towards the position at which the material releasing means isclosed. The means enclosing the solenoid valve means for preventingfinger actuation thereof may comprise a block, preferably having aninternal bore therewithin. The bore is preferably aligned with the stemof the valve. An external surface of the block preferably includes anaperture defining an end of the bore which is sufficiently proximate tothe valve means to preclude digital or finger actuation of the valve bycontact with the valve stem.

In another of its aspects, the weigh scale blender may include axiallyself-aligning means for coupling the motor to the mixing means.

Respecting the axially self-aligning means for coupling the motor to themixing means, the self-aligning coupling means may preferably furtherinclude a cylindrical female member having an axially facing centralbore formed therein. In such case, the annular female member furtherpreferably includes a pair of retractable pins preferably extending fromthe end of the member and being adapted for mating connection with themale member.

The male member is preferably cylindrical and preferably has an annularplug extending axially therefrom. The plug preferably includes anaxially tapered tip adapted for preferably complemental engagement withthe preferably axially tapered wall of the female member bore. The plugfurther preferably includes a cylindrical wall intermediate the tipportion and the male member.

The male member preferably further includes bores formed therewithin forreceipt of the retractable pins when the plug is within the femalemember bore and the axially tapered annular and cylindrical walls of themale and female members are in preferably respective complementallycontacting engagement.

In another of aspects this invention provides a weigh scale blenderhaving a frame, a weigh bin, means connected to the frame for sensingweight of the bin and any material contained therein, a mix chamberbelow the bin and connected to the frame with mixing means within themix chamber, means for selectably releasing material in the weigh bindownwardly into the mix chamber with means connecting the weight sensingmeans to the frame and damping transfer of vibration and shock motiontherebetween. The connecting means damping transfer of vibration andshock motion between the frame and the sensing means is elastomeric andis most preferably rubber.

In a yet further aspect of the invention the connecting means whichdamps transfer of vibration and shock motion between the weight sensingmeans and the frame includes an elastomeric member interposed betweenthe frame and the weight sensing means. This elastomeric member ispreferably annularly disposed about a shaft mutually received by theframe and the mounting portion of the weight sensing means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of a weigh scale blender with a liquid colorpump.

FIG. 2 is a side sectional view of apparatus enclosing solenoid valvemeans and preventing finger actuation thereof which may be provided as aportion of the weigh scale blender illustrated in FIG. 1.

FIG. 3 is a view of the apparatus illustrated in FIG. 2 taken lookingfrom the right side in FIG. 2.

FIG. 4 is a front view of part of a male member portion of axiallyself-aligning means for coupling a motor to a mixer in the weigh scaleblender illustrated in FIG. 1.

FIG. 5 is a side view of the part of the male member of the couplingmeans illustrated in FIG. 4 with certain of the hidden lines, whichwould otherwise be present, removed for drawing clarity.

FIG. 6 is a view analogous to that of FIG. 4, illustrating a femaleportion of the coupling means in a front view.

FIG. 7 is a side view of the female portion illustrated in FIG. 6.

FIG. 8 is a front view of a plug portion of the male member of thecoupling means.

FIG. 9 is a side view of the plug portion illustrated in FIG. 8.

FIG. 10 is a side view of a pin adapted to fit in and extend from thefemale portion of the coupling means illustrated generally in FIGS. 6and 7.

FIG. 11 is a side schematic view of axially self-aligning means forcoupling a motor to a mixer in the weigh scale blender illustrated inFIG. 1, showing the component parts illustrated in FIGS. 4 through 10assembled and ready for coupling of the male and female memberstogether.

FIG. 12 is a side view of a load cell and associated structureconnecting a weigh bin to a frame of a weigh scale blender includingmeans for shock and vibration isolating the load cell from the frame,where the weigh scale blender employs a single load cell.

FIG. 13 is a side view of a load cell and associated structureconnecting a weigh bin to a frame of a weigh scale blender includingmeans for shock and vibration isolating the load cell from the frame,where the weigh scale blender employs two load cells.

FIG. 14 is an enlarged view of the structure illustrated in FIG. 12 asindicated by circle AA in FIG. 12.

FIG. 15 is an enlarged view of the structure illustrated in FIGS. 12 and14 taken at circle CC in FIG. 14.

FIG. 16 is an enlarged broken side view of a load cell and associatedstructure, similar to FIG. 14, connecting a weigh bin to a frame of aweigh scale blender including means for shock and vibration isolatingthe load cell from the frame in accordance with a preferred embodimentof the invention for single load cell blenders.

FIG. 17 is an enlarged broken side view of a load cell and associatedstructure, similar to FIG. 14, connecting a weigh bin to a frame of aweigh scale blender including means for shock and vibration isolatingthe load cell from the frame in accordance with a second preferredembodiment of the invention for single load cell blenders.

FIG. 18 is an enlarged view of the structure illustrated in FIG. 13 asindicated by circle BB in FIG. 13.

FIG. 19 is a side elevation of the load cell and associated structureillustrated in FIG. 18, looking from the right side in FIG. 18.

DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE KNOWN FORPRACTICING THE INVENTION

Referring to the drawings and to FIG. 1 in particular, a weigh scaleblender together with a color addition pump are illustrated with thiscombination being indicated generally 10.

The weigh scale blender is designated generally 11 and includes ahopper, designated generally 12, supported by a frame designatedgenerally 14 which holds a weigh bin 15 into which portions of plasticresin material, and optionally liquid color material, can be metered andweighed prior to release into a mix chamber as described below. Frame 14preferably includes four upstanding members, which are preferably steelangle iron and are identified 30 with two of upstanding members 30 beingillustrated in FIG. 1. Frame 14 preferably further includes websconnecting upstanding members 30 together to provide rigidity for frame14. These webs have not been illustrated in the drawings.

Hopper 12 preferably has multiple internal compartments so that aplurality of different solid resinous materials may be dispensed fromhopper 12 into weigh bin 15 by suitable slide gates, designatedgenerally 19, located at the bottom of a given compartment of hopper 12.

Weigh scale blender 11 may further include pneumatically actuated pistonmeans 21, housed within cylinders 17, which are connected with hopper 12via slide gates 19. Piston means 21 operate in response to signals tomove slide gates 19 thereby to release material stored within hopper 12downwardly towards weigh bin 15. The pneumatic piston-cylinder actuatedslide gate combinations are designated generally 18 in FIG. 1.

Alternatively, one or more auger feeders may be used in lieu of aportion of hopper 12. Auger feeders are desirably used for componentswhich are added at 5% or less to the mix blend; however, auger feedersadd to the cycle time for each batch and reduce overall throughputrates. Hence, auger feeders are desirably optionally used only foraddition of low percentage components to the blend to be mixed.

Positioned within and preferably slidably retained in place by frame 14below weigh bin 15 is a mix chamber 20 having a mixing means which ispreferably in the form of a mixing agitator 22 rotatably disposedtherewithin. Agitator 22 is mounted for rotation about an axis 24preferably shared with a drive motor 26. Motor 26 preferably has itsdrive shaft positioned to drive mixing agitator 22 about a common axis.Drive motor 26 is preferably supported by a cantilevered support, whichhas not been illustrated in the drawing for clarity, extending laterallyfrom an upstanding member 30 of frame 14.

While the weigh scale blender illustrated in FIG. 1 has been depictedshowing a single rotatable mixing means 22, two mixers, one desirablylocated above the other, may also be used for high volume applications.Mix chamber 20 may be fabricated to be slidably removable from frame 14with mix chamber 20 being movable in a direction parallel with the axisof agitator 22.

Desirably located proximate to weigh scale blender 11 as illustrated inFIG. 1 is an optional liquid color reservoir 120 having liquid colortherein denoted 122. A pump 124 is desirably a peristaltic pump orperhaps a progressive pump or a piston pump and connects to liquid colorreservoir 120 to draw liquid color 122 from reservoir 120 by a pumpcolor feed line 126. Pump 124 preferably provides liquid color to weighscale blender 11 via mixer color feed line 128. This line connects toframe 14 of weigh scale blender 11 via tube holding fitment 130 throughwhich liquid color material 122 is introduced to the upper portion ofweigh bin 15 of weigh scale blender 11.

Pump 124 is desirably mounted at least close to, and preferably on,optional liquid color reservoir 120, as illustrated in FIG. 1. Suchlocation and mounting of pump 124 close to and desirably on top ofreservoir 120 is necessitated by the nature of the liquid color 122 inreservoir 120. Specifically, liquid color 122 is typically extremelythick and viscous. Liquid color material 122 can be pumped usingpositive pressure a much longer distance than the liquid color material122 can be drawn by suction or vacuum. Pumping using pump 124 mayproduce pressures of up to 100 pounds per square inch. Suction, even ifa full vacuum is achieved, relies on air pressure to move liquid andhence the maximum possible pressure is about 14.7 psi. Accordingly, itis important to locate pump 124 close to reservoir 120 in order thatmost efficient delivery of liquid color 122 to weigh scale blender 11may be effectuated. Suitable pumps for use as liquid color pump 124 areavailable from Maguire Products, Inc. in Aston, Pa.

Weight of material in weigh bin 15 is preferably sensed by load cells 32which are preferably connected to microprocessor control means 34 whichregulates operation of the weigh scale blender 11 through electricalconnection with the load cells, the solenoid actuators for the solenoidvalves, the motor, the liquid color pump and the like.

The microprocessor provides control of weigh scale blender 11 bymonitoring, preferably on a continuous basis, weight of material, ifany, at a weighing station defined by weigh bin 15. By sensing weight ofweigh bin 15 and opening appropriate slide gates 19, microprocessorcontrol means 34 serially meters respective components of solid granularresinous material to the weighing station defined by weigh bin 15 untila pre-selected weight of each of the respective components has arrivedat the weigh station.

Microprocessor 34, through monitoring weight of the weigh bin andmaterial therewith, optionally controls metering liquid color to theweighing station defined by weigh bin 15 and adds the metered liquidcolor to the respective components of solid granular material at theweigh station until a pre-selected weight of liquid color has arrived atthe weigh station and has been added to the batch of solid materialdefined by the collective components in weigh bin 15.

Blender 11 preferably operates by blending components by weight based onsettings which are preferably shown on a master controller portion ofmicroprocessor controller 34. Blending is desirably done in batches of2,000, 4,000, 9,000 or 18,000 grams, depending on the amount desired.Each component is preferably dispensed separately into weigh bin 15 andthen all components are dropped together into mixing chamber 20.

Blender 11 is designed to mount directly over the feed throat of aprocess machine used to mold or extrude plastic material with blender 11being bolted or otherwise fixedly connected to the process machine.

When exclusively solid materials are being blended, typically regrindmaterial is dispensed first according to the percent of regrind materialrequired. If no regrind material or a limited amount of regrind materialis present, then portions of natural material, solid color material andadditive material are increased to bring about a full batch weight.Natural material is typically added second. The amount of naturalmaterial added is preferably calculated by microprocessor 34 to leaveexactly the right amount of room in the mix chamber for the solid colormaterial and additive material. Once the natural material fill portionof the cycle has been completed, the exact weight of the naturalmaterial that has been actually dispensed is determined to detect anyerrors. Based on this actual weight of natural material dispense, coloradditive in the form of solid color additive material is metered intothe weigh bin and then other solid additive materials are metered intothe weigh bin in the same manner. All components are then dumped intothe mixing chamber which is preferably continuously running.

In the case where liquid color material is used in place of solid colormaterial, the liquid color material is preferably added to the weigh binlast.

Microprocessor control means 34 provides the serially metered componentsand the optional preselected weight of liquid color material unitarilyto a mixing station defined by mix chamber 20 by opening weigh bin 15thereby to permit the materials vertically supported thereby to falldownwardly into the mix chamber. Weigh bin 15 is preferably opened by apneumatic piston-cylinder combination, which is controlled bymicroprocessor 34 and has not been illustrated in the drawings fordrawing clarity. The pneumatic piston-cylinder combination is mounted onframe 14 and is connected to weigh bin 15 so that weigh bin 15 opensresponsively to movement of the piston member of the piston-cylindercombination.

In mix chamber 20 the solid material components which have beenpreferably unitarily supplied and serially metered to weigh bin 15, andoptionally a pre-selected weight of liquid color material, are mixedinto a blend preparatory to being supplied to the manufacturingprocessing machine such as a molding press or an extrusion machine.

When the optional liquid color is introduced to the material to beblended in weigh bin 15 and has been dropped into mix chamber 20, themixer portion, specifically mixing agitator 22 of weigh scale blender11, effectively precoats the material pellets, which have come fromhopper 12 through weigh bin 15 into mix chamber 20, with the liquidcolor. This produces superior color dispersion in final production partsproduced by injection or compression molding or by extrusion, providinga substantial improvement over results achieved when liquid colormaterial is blended with plastic resin by metering liquid color directlyinto the throats of plastic material processing machines such asextruders and molding presses. Supplying liquid color 122 to weigh bin15 of weigh scale blender 11 using pump 124 permits accuratecomputerized tracking of liquid color material used.

Liquid color 122 by its very nature presents a continuous potential forsubstantial clean-up difficulties in the event of a spill, malfunctionof equipment or breakage of any of the feed lines such as pump colorfeed line 126 or mixer color feed line 128. Providing liquid color 122directly into weigh bin 15 of weigh scale blender 11 provides apractical means of handling liquid color 122 and minimizes clean-upproblems in the event of equipment failure.

Desirably, monitoring of weight of material at the weighing station isperformed continuously by the microprocessor continuously digitallysensing signals supplied by load cells which are depicted schematicallyin FIG. 1 and identified generally 32 therein; the load cells areinterposed between weigh bin 15 and frame 14. Weigh bin 15 is suspendedby and from load cells 32 with respect to frame 14. Depending on thesize of weigh bin 15, a single load cell or multiple load cells may beused.

Most desirably metering of liquid color to the weighing station definedby weigh bin 15 is performed peristaltically.

Microprocessor control means 34 actuates solenoid controlled preferablypneumatic valves, which are not illustrated in FIG. 1 but which areshown schematically as 36 in FIGS. 2 and 3, to provide pneumaticpressure via suitable conduits to piston-cylinder slide gatecombinations 18. Solenoid valves 36 actuated by control means 34 areeach individually connected via two suitable conduits, which arepreferably flexible plastic tubing, to associated individualpiston-cylinder slide gate combinations 18 to open and close individualslide gates 19 by application of pneumatic pressure to an appropriateside of a piston 21 portion of a piston-cylinder combination 17.

Each solenoid valve 36, specifically the core of the solenoid, isspring-biased towards a position corresponding to that at which thepiston member 21 of a piston-cylinder slide gate combination 18associated with a given solenoid valve 36 is at a preferred position,referred to as the default position, for operation of weigh scaleblender 11. When due to a change in operational factors such as removalof a blended batch from mix chamber 20, need for additional material inweigh bin 32, commencement of a loading cycle or the like,microprocessor control means 34 senses that it is required to actuate agiven piston of a piston-cylinder slide gate combination 18. One examplemight be to open one of the compartments within hopper 12 to add anamount of component material in that compartment to weigh bin 15. Insuch case microprocessor control means 34 actuates the solenoid valveassociated with the given piston-cylinder slide gate combination ofinterest thereby moving the piston member of the appropriatepiston-cylinder slide gate combination 18 from the default position to aposition at which a given hopper slide gate is open or other desiredaction has been taken.

Referring to FIG. 2, each solenoid valve, one of which has beendesignated generally 36, includes a valve member 38 and a solenoidactuator 40, both of which have been shown in schematic form in FIG. 2.Suitable wiring, which has been designated 42 in FIG. 2, leads fromsolenoid actuator 40 to microprocessor control means 34, which has notbeen illustrated in FIG. 2.

Each solenoid actuator 40 includes a core member, not illustrated inFIG. 2, which when actuated due to voltage being applied to anassociated coil, moves axially respecting the coil and actuatesassociated valve member 38 against the bias of a spring, also notillustrated in FIG. 2, which continuously urges the core towards thedefault position.

The solenoid actuated valves function to move pistons within aircylinders by pressurizing one side of a piston and opening the otherside to the atmosphere. There is no vacuum involved, just pressure aboveatmospheric pressure and ambient atmospheric pressure.

Valves 36 are preferably four-way solenoid valves, meaning that eachvalve has four ports. These are a pressure port, an exhaust port and twofunction ports which are connected to the given air cylinder of interestby the flexible plastic tubing. The pressure and exhaust ports areconnected to air pressure and ambient atmosphere respectively by way ofa manifold 44 which is drilled to provide common pressure and exhaustports for all of the solenoid actuated valves.

The valve in its normally at rest or default state connects pressurizedair to an “A” port and ambient air to a “B” port. When the valve isenergized the A port is switched to ambient air and the B port isswitched to the pressurized air. Two air lines 25 preferably connecteach solenoid actuated valve to a given air cylinder with one solenoidactuated valve being provided for and connected to each air cylinder. Atrest or default, a piston 21 within a given air cylinder 17 ispreferably extended so that the slide gate actuated by piston 21 isclosed. When the associated valve 36 is energized, piston 21 retracts,the associated slide gate 19 opens and material in the hopper isdispensed downwardly.

Solenoid actuated valves 36 may also be used to operate the weigh bindump and further may be used to operate an optionally flow control valveserving the shutoff and exit opening at the bottom of the blender. Ifthe blender is fitted with such a flow control at the bottom, the flowcontrol valve may hold material in the chamber for a time period forbetter mixing.

Each solenoid valve 36 preferably has associated therewith a pair ofpneumatic conduits, each of which is connected to manifold 44 asillustrated in FIG. 2. One of the pneumatic conduits preferably leads toa pressurized air inlet portion of manifold 44 where the air inlet or apressurized portion of manifold 44 has been designated 50 and isillustrated as a conduit extending longitudinally through manifold 44.Similarly, a second one of pneumatic conduits associated with a givensolenoid valve 36 is an unpressurized, ambient air conduit andcommunicates with an exhaust portion of manifold 44 where the exhaustportion has been designated 52 in FIG. 2 and has similarly beenillustrated as a conduit extending longitudinally through manifold 44.

Valve 38 operates to connect either positive air pressure, as receivedby pneumatic conduit 55 communicating with pressurized air inlet 50 orambient pressure as present in pneumatic conduit 53 communicating withthe exhaust or ambient portion 52 of manifold 44 to default and signalconduits 51, 57 respectively as illustrated in FIG. 2. Apertures formedin manifold 44 define open ends of the respective pressurized andambient conduits 51′, 57′ which communicate with correspondingpressurized and ambient conduits 51′, 57′ of valve 36 with apertures56′, 56′ defining outlets of conduits 51′, 57′ from manifold 44 as shownin FIG. 3. One of apertures 56′, 56′; has been illustrated with afitting 54 in FIG. 2. Use of the prime notation in this paragraph servesto distinguish portions of conduits 51′, 53′, 55′ and 57′ formed inmanifold 44 from the portions of those corresponding conduits forming apart of a respective solenoid valve 36.

Solenoid valves 36 and especially solenoid actuators 40 of valves 36 arepreferably maintained within an enclosed housing designated generally 58in FIG. 2. Housing 58 is preferably of sheet metal construction and, asillustrated in FIG. 2, can be constructed from multiple pieces securedtogether by nut and bolt combinations, by sheet metal screws or by othermeans. Closed housing 58 preferably fits around solenoid actuators 40and specifically preferably encloses face surfaces 60 of solenoidactuators 40 in which or from which the movable core of the solenoidportion of solenoid valve 36 may be accessed. In FIG. 2, the solenoidcore and specifically the tip portion thereof of valve 36 has beenillustrated schematically as 62.

Retained within closed housing 58 is a block 64 which includes bores 66therein. Block 64 is fabricated of a size and positioned within housing58 so as to have a planar surface 68 which is in close proximity andpreferably in facing complemental contact with all of faces 60 ofsolenoid actuators 40 via which the core members 62 of given solenoidvalves 36 may be accessed.

Block 64 is retained rigidly and fixedly within closed housing 58 andpositioned with bore 66 communicating with tip 62 of the movablesolenoid core. Due to the close placement of face 68 in preferablyessentially complemental, and in any event close proximity to, andparallel disposition with face 60, block 64 makes tip 62 of the solenoidcore effectively inaccessible by an operator's fingers. Block 64 ispreferably constructed of sufficient size to adequately overlap the areaor aperture, as illustrated in FIG. 2, within which or via which tip 62of a movable solenoid core may be accessed. Block 64 is preferablyfabricated from a solid piece of aluminum or other metal or of plastic.

Push rods 70 may be provided within bore 66 for manual actuation ofsolenoid core tips 62 by manually pushing on a remote end of A rod 70,denoted 72 in FIG. 2.

In jurisdictions where safety regulations prohibit manual actuation ofsolenoid valves, manual override of pneumatically actuated solenoidvalves 36, rods 70 would not be present. In such case, due to thepresence of block 64 override of solenoid valves 36 could only beaccomplished using a suitable secured tool, thereby preventing directmanual actuation and override of a solenoid valve 36.

Preferably manifold 44, solenoid valves 36, closed housing 58 and theassociated structure are mounted on the bottom side of a housing formicroprocessor 34, which is provided in cantilevered fashion extendingfrom upstanding members 30 of frame 14, as illustrated in FIG. 2.Manifold 44, associated solenoid valves 36, closed housing 58 and thestructure enclosed therewithin may be secured to the bottom of thehousing for microprocessor 34 which has been designated 74 in FIG. 2 viasuitable bolt and nut combinations 76, as illustrated in FIGS. 2 and 3.

Referring to FIGS. 4 and 5 of the drawings, the axially self-aligningmeans, designated generally 80 in FIG. 1, for coupling drive motor 26 tomixing agitator 22 preferably includes male and female portions wherethe component parts of the female portion are illustrated in FIGS. 6, 7and 10 and the component parts of the male portion are illustrated inFIGS. 4, 5, 8 and 9.

Axially self-aligning means 80 for coupling motor 26 to mixing means 22preferably has a female portion which is preferably generallycylindrical in shape and has been designated generally 78 in FIGS. 6 and7. The coupling apparatus itself is designated generally 80, and isillustrated in schematic form in FIG. 1.

Female member 78 preferably has an axially facing central bore 82 formedtherein as illustrated in FIG. 7. Bore 82 preferably includes an axiallytapered annular wall 84 which communicates with an end 86 of preferablycylindrical female member 78. End 86 is preferably in the form of aplanar, preferably annular surface and is adapted for mating connectionwith a male member 88, illustrated in FIGS. 4 and 5, of axiallyself-aligning coupling means 80. The manner in which female member 78matingly connects with male member 88 to assure axial alignment ofcoupling means 80 is illustrated in FIG. 11.

Female member 78 further includes a cylindrical wall 90 forming aportion of axially facing central bore 82. Wall 90 adjoins axiallytapered annular wall 84 at one extremity thereof and adjoins an annularbottom 92 of central bore 82 at a second axial extremity. Axially facingcentral bore 82 extends entirely through female member 78 as a portionof reduced diameter indicated as 94 in FIG. 7; the reduced diameterportion 94 of axially facing central bore 82 has not been illustrated inFIG. 11 to facilitate drawing clarity and understanding of the operationof axially self-aligning coupling means 80.

Female member 82 may be retained in place on the shaft of drive motor 26or on the shaft of mixing agitator 22 by keying the selected shafttogether with a set screw, for which mating threads and a suitablereceiving bore have been illustrated in FIG. 6. The keyed arrangement inthe reduced diameter portion 94 of bore 82 of female member 78 isillustrated in FIG. 6. The keyway, which has not been numbered, has beenillustrated in dotted lines in FIG. 7. The set screw and threaded borefor the set screw, illustrated generally in FIG. 6, have been omittedfrom FIG. 7, and from FIG. 11, to aid drawing clarity.

Female member 78 further preferably includes a pair of closed bottombores 98, 98′, which are preferably disposed diametrically opposite fromone another and formed in facing surface 86 of female member 84 at aposition outboard of the outer extremity of axially tapered annular wall84 in such surface. Closed bottom bores 98 are provided to housespring-loaded pins 100, one of which has been illustrated in FIG. 10.Pins 100 are preferably spring-loaded against the bottom of closedbottom bores 98 to protrude from surface 86 towards male member 88. Pins100 are biased outwardly from bottoms of closed bottom bores 98 bysprings 114 which are preferably fitted within and extend from pins 100as illustrated generally in FIGS. 10 and 11.

As illustrated in FIGS. 4, 5 and 11 male member 88 is generallycylindrical in form and has an annular plug 102 extending therefromwhere the plug has been illustrated in FIGS. 8 and 9. Plug 102 ispreferably manufactured from a thermoplastic material such as those soldunder the trademarks Nylon, Delrin and Celcon. Plug 102 preferablyincludes a cylindrical portion 104 and an axially tapered portion 106.Cylindrical portion 104 is preferably sized for close complementalfitting with cylindrical wall 90 of axially facing central bore 82 infemale member 78. Tapered portion 106 is preferably tapered at the sameangle relative to the axis as axially tapered annular wall 84 of axiallyfacing central bore 82 in cylindrical female member 78. Plug 102 ispreferably held in place at the center of cylindrical male member 88 bysuitable set screws, machine screws and the like which have not beenillustrated in the drawings.

Cylindrical male member 88 further preferably includes a pair ofdiametrically opposed bores 108, 108′ which are spaced away from theaxis of male member and positioned to receive spring-loaded pins 100protruding from closed bottom bores 98 of cylindrical female member 78of coupling member 80. The receipt of spring-loaded pins 100 extendingfrom female member 78 by diametrically opposed bores 108, 108′ formed inmale member 88 is depicted schematically by dotted lines P in FIG. 11.When cylindrical female member, specifically surface 86 thereof, issufficiently proximate to facing surface 110 of cylindrical male member88 that retractable pins 100, protruding from closed bottom bores 98,engage bores 108 in cylindrical male member 88 as depicted by dottedlines P, tight coupling with essentially no rotational play between maleand female members 88, 78 is effectuated.

As illustrated in FIG. 11 the coupling member 80 of which principalcomponents are illustrated in FIGS. 4 through 10 is axiallyself-aligning due to the configuration of plug 102, specifically thewall profile thereof which is initially tapered and thereaftercylindrical. When initial tapered portion 106 of plug 102 encounters thecorrespondingly tapered portion defined by axially tapered annular wall84 in female portion 78, the taper between the two surfaces,specifically upon contact therebetween, causes male and female couplingmembers 78, 88 to axially align, thereby providing a self-aligningcoupling which is effectuated as pins 100 protruding from closed bottombores 98 find bores 108 in face 110 and extend thereinto. Engagement ofpins 100 and bores 108 provides excellent torque transfer between maleand female members 88, 78 constituting axially self-aligning torquecoupling 80.

Spring loading of pins 100, as the male and female members of couplingassembly 80 approach one another and surfaces 86, 110 become proximateone another, permits those pins to retract slightly into closed bottombores 98 as the extremities 112 of the pins protruding from bores 98contact surface 110. Hence any destructive forces are ameliorated aspins 100, specifically outermost surfaces 112 thereof, contact surface110 and run on surface 110 due to relative rotation between the male andfemale members until pins 100 find bores 108, 108′ and extend thereinto,thereby effectuating tight connection between the male and femalemembers of axially self-aligning coupling means 80.

FIG. 12 illustrates a portion of a single load cell embodiment of theinvention including means for connecting the load cell to frame 14 ofweigh scale blender 11 for damping transfer of vibration and shockmotion between frame member 30 and load cell 32. In the single load cellembodiment the means for connecting the load cell to the frame of theweigh scale blender includes structure for connecting the weigh bin 15to the load cell 32 preferably in a manner that weigh bin 15A iseffectively cantilevered from load cell 32.

FIG. 13 illustrates a portion of a dual load cell weigh scale blenderincluding means connecting the load cells to frame 14 of weigh scaleblender 11 and damping transfer of vibration and shock motiontherebetween. In the dual load cell embodiment weigh bin 15 ispreferably supported by and preferably rests directly on a pair ofbrackets, which are generally of zig-zag shape and are designatedgenerally 23 in FIG. 13. Weigh bin 15 preferably rests directly onbrackets 23 which transfer weight of weigh bin 15 and any materialcontained there into load cells 32.

As illustrated in FIG. 14 which is an enlarged version of the structureillustrated in circle AA in FIG. 12, load cell 32 is mounted on andcontained within a load cell enclosure box designated generally 154.

Box 154 has a vertically upstanding portion 174 and upper and lowerhorizontally extending portions 176 and 178 respectively.

The weigh bin has been designated 15A in FIG. 14, with the letter “A”denoting that the weigh scale blender has but a single load cell 32.

The weigh scale blender illustrated in FIG. 1 has two load cells 32.Larger capacity weigh scale blenders are provided with two load cellswhereas smaller capacity weigh scale blenders utilize only a single loadcell, for economy purposes.

Referring still to FIG. 14 there is connected to weigh bin 15A a weighbin bracket 156A which is fixedly secured to weigh bin 15A. Weigh binbracket 156A includes a vertically extending portion designated 180 inFIG. 14, which is preferably fixed in facing complemental contact withweigh bin 15A.

A portion 182 of weigh bin bracket 156 extends horizontally outwardlyfrom vertical portion 180 of the weigh bin bracket at the upperextremity thereof while a corresponding horizontally extending portion184 extends laterally outwardly, in a horizontal direction, from thelower extremity of vertical portion 180 of the weigh bin bracket asillustrated in FIG. 14. An upper outer extremity of weigh bin bracket156 extends vertically downwardly from an outboard extremity ofhorizontally extending portion 182; this vertically downwardly extendingportion of bracket 156 is designated 186 in FIG. 14. A correspondinglower vertically upwardly extending portion of weigh bin bracket 156 isdesignated 188 in FIG. 14 and extends vertically upwardly from thelateral outward extremity of horizontally extending portion 184 of weighbin bracket 156.

Vertically extending extremities 186, 188 provide an open envelopestructure which permits weigh bin 15A and particularly weigh bin bracket156 to move slidably horizontally, in a direction perpendicular to theplane of the paper in FIG. 14, to be positioned so that weigh bin 15Aeffectively hangs on and is cantilevered from load cell 32.

Affixed to load cell 32 for receiving the weight load and transferringthe same to load cell 32 is a load transfer beam 170. Load transfer beam170 has an upper horizontally extending portion 190 fixedly connected byscrew 214 to the upper surface of load cell 32, a lower generallyhorizontally extending portion 192 and a central portion 194 extendingbetween upper and lower portions 190, 192 and slightly canted from thevertical illustrated in FIG. 14. Load cell 32 senses the weight load ofweigh bin 15A and any material contained therein by strain resulting atthe upper surface of load cell 32 where load transfer beam 170 isfixedly connected thereto. Load cell 32 is fixed to load cell enclosurebox 154, particularly to lower horizontally extending portion 178 ofload cell enclosure box 154 via suitable screws 222, only one of whichis visible in FIG. 14.

Affixed to central portion 194 of load transfer beam 170 is a loadtransfer plate designated 196 in FIG. 14. Plate 196 is preferablyslotted at the central portion thereof with the slot designatedgenerally 198 in FIG. 14. Slot 198 is relatively short, preferably beingonly about 1 inch in length, and is provided to receive a tab member 168which extends laterally from vertical portion 180 of weigh bin bracket156, as weigh bin 15A is slidably positioned on and supported by loadtransfer plate 196. When weigh bin 15A is fully in position and tab 168has traversed the relatively short length of slot 198, tab 168disengages from slot 198 and the weigh pan moves slightly downwardly,with the upper interior of weigh bin bracket 156 coming to rest on thevertical upper extremity of load transfer plate 196. In this positionweigh bin 15A is effectively cantilevered with respect to load cell 32and the load represented by the weight of the weigh bin 15A and anymaterial contained therein is transferred directly to load cell 32 byload transfer plate 196 and load transfer beam 170, with load cell 32effectively sensing the weight of material contained within bin 15A.

To protect load cell 32 from contact and possible damage by operators,load cell 32 is preferably within load cell enclosure box 154 asillustrated in FIG. 14. Load cell enclosure box 154 is in turnpreferably connected to a load cell mounting plate 152 by suitable nutand bolt combinations as illustrated in FIG. 14 and as shown in greaterdetail in FIG. 15. The nut and bolt combinations 206, which secure loadcell enclosure box 154 to load cell mounting plate 152, are spaced awayfrom and do not contact upstanding members 30 of frame 14. This isillustrated in FIG. 15.

Load cell 32 and particularly load cell 150 are connected to frame 14and specifically to upstanding members 30 by load cell assembly 150which desirably includes a plurality, preferably two, of mountingbolt/lock nut/grommet combinations, one of which has been designatedgenerally 161 in FIG. 14. Mounting bolt or screw 162 extends throughload cell mounting plate 152 via a suitable aperture formed therein andalso through a suitable apertures in upstanding frame member 30.Mounting bolt on screw is retained in place by a lock nut 166. A rubbergrommet 158 is positioned preferably in the hole through load cellmounting plate 152 such that there is no metal-to-metal contact betweenload cell mounting plate 152 and upstanding frame member 30. Rubbergrommet 158 cushions load cell mounting plate 152 with respect toupstanding frame member 30.

Similarly, because rubber grommet 158 has two exterior donut-likeportions, designated 200, 202 in FIG. 14, and an internal hollowcylindrical portion designated 204 in FIG. 14, there is nometal-to-metal contact between mounting screw or bolt 162 and load cellmounting plate 152. The soft rubber of grommet 158 cushions load cellmounting plate 152 against any contact and effectively shock andvibration isolates load cell mounting plate 152 from mounting screw orbolt 162 and hence from upstanding frame member 30.

Referring to FIG. 19 where the mounting arrangement for a load cell 32respecting upstanding frame members 30 in a two load cell weigh scaleblender is illustrated, load cell mounting plate 152 is illustrated inFIG. 19 as is load cell enclosure box 154. From FIG. 19 it isimmediately apparent that the mounting bolt/lock nut/grommetcombinations 161, which secure load cell mounting plate 152 toupstanding frame members 30, preferably reside in apertures formed inload cell mounting plate 152 which are preferably well removed laterallyfrom load cell 32.

As is further apparent from FIG. 19, nut and bolt combinations 206 whichsecure load cell enclosure box 154 to load cell mounting plate 152 alsoare preferably well removed laterally from upstanding frame members 30and hence from mounting bolt/lock nut/grommet combinations 161.

As further illustrated in FIG. 19, load cell mounting plate 152 ispreferably generally rectangular in configuration and forms what wouldotherwise be an open side of load cell enclosure box 154. Apertures areprovided in load cell enclosure box 154 for passage therethrough ofstructure connecting the weigh bin to the load cell. In the embodimentillustrated in FIG. 14, openings in load cell enclosure box 154 andspecifically in vertically upstanding portion 174 thereof are designated208, 210 for passage of upper and lower generally horizontally extendingportions 190, 192 of load transfer beam 170 therethrough.

FIG. 16 illustrates another embodiment of a load cell assemblydesignated generally 150. The embodiment illustrated in FIG. 16 issimilar to that illustrated in FIG. 14 in that load cell 32 is locatedbetween upstanding members 30 of frame 14 and a weigh bin 15A, and isfurther similar to the structure illustrated in FIG. 14 in that weighbin 15A is effectively cantilevered from load cell 32.

The structure illustrated in FIG. 16 differs from that illustrated inFIG. 14 in that load cell mounting plate 152 is positioned outboard ofupstanding frame members 30. Load cell 32 is clearly inboard of framemembers 30, between frame members 30 and weigh bin 15A. The mountingbolt/lock nut/grommet combination 161 is essentially the same asillustrated in FIG. 14; a washer 164 is provided in the structureillustrated in FIG. 16 to facilitate even application of moderatepressure to grommet 158 upon rotation of lock nut 166 on a shaft portionof mounting bolt 162. The arrangement and relative location of themounting bolt/lock nut/grommet combinations 161 securing the load cellmounting plate 152 to upstanding frame member 30 and the positions ofnut bolt combinations 206 securing load cell enclosure box 154 to loadcell mounting plate 152 shown in FIG. 16 are preferably essentially thesame as depicted in FIG. 19 and as discussed above relative to FIG. 14.

FIG. 17 illustrates yet another embodiment for a single load cell weighscale blender. The structure in FIG. 17 is similar to that illustratedin FIGS. 14, 15 and 16. However, as is illustrated in FIG. 17, grommet158 of the mounting bolt/lock nut/grommet combination 161 is provided inposition about frame member 30, as contrasted to load cell mountingplate 152. In this position grommet 158 prevents any metal-to-metalcontact between mounting bolt 162 and upstanding frame member 30. Awasher 172 is provided to distribute force resulting from head 162pressing against grommet 158.

In the structure illustrated in FIG. 17, bolt 162 extends not onlythrough upstanding frame member 30 but past load cell mounting plate 152and through an aperture formed in vertically upstanding portion 174 ofload cell enclosure box 154. Lock nut 166 bears against the exteriorsurface of vertically upstanding portion 174 of load cell enclosure box154 as illustrated in FIG. 17.

As a further variation in FIG. 17 the load transfer plate has beendesignated 196A and includes an angled tip portion 212 at the uppervertical extremity thereof. Angled tip portion 212 fits against aninwardly facing surface of upper vertically extending extremity of 186of weigh bin bracket 156 and against a downwardly facing surface ofupper end horizontally extending portion 182 of weigh bin bracket 156 toprevent rotation or canting of weigh bin 15B relative to load cell 32and especially load transfer beam 170. This results in preferably flush,facing contact between vertical portion 180 of weigh bin bracket 156 andload transfer plate 196A. Similarly to the embodiments illustrated inFIGS. 14 and 16, load transfer plate 196A is fixedly connected to loadtransfer beam 170 while weigh bin bracket 156 is fixedly connected toweigh bin 15B; some small sliding complemental motion is permittedbetween load transfer plate 196A and weigh bin bracket 156 to facilitateeasy installation of the weigh bin and removal thereof for cleaning.Such sliding motion is perpendicular to the plane of the paper in FIG.17.

Respecting orientation and relative location of mounting bolt/locknut/grommet combination 161 vis-a-vis nut/bolt combinations 206 for thestructure illustrated in FIG. 17, mounting bolt/lock nut/grommetcombination 161 is preferably laterally displaced substantially fromload cell 32, with a mounting bolt/lock nut/grommet combination 161positioned on either side of load cell 32 at a common vertical positionrelative to load cell 32. Nut/bolt combinations 206 are preferablylocated inboard of the mounting bolt/lock nut/grommet combinations 161Bin a manner similar to that illustrated in FIG. 19. The load cellenclosure box 154 illustrated in FIG. 17 is longer in lengthlongitudinally that illustrated in FIG. 19 in order to horizontallyoverlap to at least some extent the two vertically upstanding members 30forming a portion of frame 14, in order that grommet 158 and bolt 160could be positioned in frame member 30 and still engage the facing sideof load cell enclosure box 154 as illustrated in FIG. 17.

Structure for vibration and shock-isolating load cells 32 fromupstanding members 30 of frame 14 in a dual load cell weigh scaleblender is illustrated in FIGS. 13, 18 and 19. A load transfer beam170-2 is fixedly connected to an upper portion of load cell 32 bysuitable screw connectors 214. Load transfer beam 170-2 in theembodiment illustrated in FIGS. 18 and 19 is of generally invertedU-shaped configuration, having a horizontal portion 216 extending acrossthe top of load cell 32 and having vertically downwardly directedlateral extremities 218, 220.

Load cell 32 is fixedly connected to the bottom of load cell enclosurebox 154 via screw connectors 222 illustrated in FIGS. 18 and 19. Screwconnectors 222 which rigidly hold the load cell in position vis-a-visthe load cell enclosure box. Hence the bottom of the load cell is fixedwhereas the upper portion of the load cell, where the load is sensed, isfree to deflect in response to loads applied as result of material beingin the weigh bin.

Fitting slidably within apertures, which have not been shown in thedrawings, formed in horizontal portion 216 of load transfer beam 170-2are a pair of hanger screws 224 having long shafts. Each of hangerscrews 224 fit slidably through an aperture in horizontal portion 216 ofload transfer beam 170-2 with the shaft portions of screws 224 passingslidably through the apertures but the head portions of hanger screws224 being too large. As a result hanger screws hang freely fromhorizontal portion 216 of load transfer beam 170-2. Preferably fittedabout the shafts of hanger screws 224 are coil springs 160 which serveto provide some bias and resilience in the event hanger screw 224 and/orweigh bin 15, which is suspended therefrom, as illustrated in FIG. 13,are jostled.

Located at lower extremities of hanger screws 224 are nut and washercombinations 226. Nuts of combinations 226 are threaded on hanger screws224.

Supported by the washers of combinations 226 are zig zag brackets 23which support weigh bin 15.

With this construction the entire weight of weigh bin 15 and anymaterial contained therein is transferred to the washers of combinations226 by zig-zag brackets 23. This results in transfer of the weightthrough hanger screws 224 to horizontal portion 216 of load transferbeams 170-2 with load cell 32 thereby being stressed and sensing theweight of bin 15 and any material contained therein.

In the dual load cell embodiment illustrated in FIGS. 13, 18 and 19 theload cell mounting plate 152 has been depicted outboard of frame members130.

In FIG. 18 grommet 158 has been depicted as being partially occluded byload cell mounting plate 152, for purposes of drawing clarity. Similarlyto the other embodiments illustrated, mounting bolt/lock nut/grommetcombination 161 isolates load cell mounting structure 150 andparticularly load cell mounting plate 152 from shock and vibration whichis present in vertical frame members 30, by virtue of rubber grommet 158completely separating mounting bolt 162 from load cell mounting plate152 or frame 30; grommet 158 additionally separates load cell mountingplate 152 from frame 30, in the manner described above for the singleload cell embodiments.

For both the single and dual load cell versions of the weigh scaleblender, grommet-connecting the load cell mounting structure to the loadcell mounting plate, in the embodiments in which the grommet engages theload cell mounting plate, or grommet-connecting the load cell mountingstructure and mounting plate to the frame members, is best accomplishedusing just a pair of grommet connectors, aligned along a horizontallyextending longitudinal or axial axis. Having the grommet connectorshorizontally aligned axis provides an axis about which the load cell (orcells in the dual load cell versions of the weigh scale blender) mayslightly rotate in response to the damped vibration or shock loading;the damping results from presence of the grommet(s). This arrangementseems to be superior to mounting arrangements in which the grommetmounts are provided in arrangements which are both horizontally andvertically aligned, such as at the corners of a rectangle, or otherarrangements which due to their geometry do not provide for an axisabout which the load cell and its mounting structure may move inresponse to shock and vibration in the frame of the weigh scale blender.

Finally, it is important that the mounting bolt not be turned tootightly, compressing the grommet excessively. If the bolt is too tight,the grommet, being highly compressed, has its shock and vibrationdamping properties compromised. For best results, the mounting boltshould only be tightened to a degree at which the grommet is justshowing the slightest bit of visually detectable deformation due tobeing compressed.

Suitable load cells are available from Tedea Huntleigh, an Israelicompany. Model 1010 load cells available from Tedea Huntleigh areparticularly suitable.

Grommet 158 is available from NTT/Smith in the United States as partnumber 920-2170. This grommet has an inside diameter of one quarterinch, an outside diameter of ⅝ of an inch and a groove width of{fraction (1/16)} of an inch, thereby permitting the grommet to fiteasily within load cell mounting plate 152. This grommet has a groovediameter of ⅜ of an inch and an overall thickness of one quarter of aninch.

Suitable solenoid actuated valves are available in the United Statesunder the trademark MAC; the model 45A-L00-DDAA-1BA9 is particularlysuitable.

I claim the following:
 1. A weigh scale blender comprising: a. a frame;b. a weigh bin; c. means, connected to said frame, for sensing weight ofsaid bin and any material contained therein; d. a mix chamber connectedto said frame, including mixing means therewithin; e. means forselectably releasing material from said bin into said mix chamber; f.means intermediate said sensing means and said frame for dampingtransfer of vibration and shock motion therebetween said sensing meansincluding a housing; g. at least one elastomeric member between saidsending means and said frame; and h. said connecting means connectingsaid housing to said frame at a plurality of positions with one of saidelastomeric rubber vibration damping members at each of said positionsseparating said housing from said frame.
 2. The blender of claim 1wherein said damping means further comprises a plurality of axiallyaligned elastomeric connecting means.
 3. The blender of claim 1 whereinsaid damping means further comprises a plurality of axially alignedelastomeric connecting means.
 4. The blender of claim 3 wherein saidelastomeric rubber means is a rubber grommet.
 5. The blender of claim 3wherein said elastomeric means is a rubber grommet.
 6. The blender ofclaim 5 wherein said grommet separates a mounting plate from said frame.